For piecing I use 1.8-2.2 stitch length setting. There's a formula to convert that to stitches per inch, which formula I forget. For machine quilting I've been using 2.5 setting. Some of my machines have a stitch made to resemble hand quilting at either 10 or 12 stitches per inch. Just be aware for piecing, that it's hard(er) to pick out the 1.8!